Foldable, boot loadable, insertable air damper device

ABSTRACT

A foldably tensioned boot loadable air damper device for controlling the flow of air through ductwork, and a method of installing same. The damper device includes an actuator having a retractable member and a pivoting member, wherein the pivoting member is operatively connected to the retractable member of the actuator. The damper device also includes at least one support base supporting the actuator and the pivoting member with respect to each other, a foldable damper blade attached to the pivoting member, and at least one tensioned hinge member operatively connected to the foldable damper blade for unfolding the damper blade. The damper device may be inserted through a register boot and into a ductwork when folded.

TECHNICAL FIELD

Certain embodiments of the present invention relate to air dampers. Moreparticularly, certain embodiments of the present invention relate to airdampers that are installed into air ducts.

BACKGROUND

Today, airflow control systems are used in retrofit applications inductwork, mainly to control a room or area's temperature and/or climate.An example of a type of control system that is utilized is a damper,which may generally be a valve or plate that stops or regulates the flowof air inside a duct, chimney, variable air volume box, air handler, orother air handling equipment. A damper can be used to shut off theairflow into various rooms or to regulate its temperature and climate.Various damper apparatuses utilize manual and/or automatic functions toadjust the airflow into the designated room or area, and thereby controlits temperature qualities. However, when applying airflow controltechniques to retrofit applications, reconfiguring the ductwork is veryexpensive because of the time and material required to modify suchductwork and the inability to access ductwork between floors or abovefinished ceilings, for example. Examples of dampers, when there isenough access room within the ductwork, include installation of eithertrunk dampers in the main trunks or branch dampers near the main truck.However, there are many instances where portions of the ductwork areinaccessible to these types of dampers, and other methods and devicesare necessary. Louvered dampers, for example, may not provide a completeshutoff of the airflow.

Other considerations that may be taken into account are issues of noiselevel and damper size. If a damper is too large, then the damper isunusable because it is not able to fit through an opening of theductwork. For example, if the cross section of the damper is too large,it may not be installed through a standard register boot. Additionally,damper and blade positioning are important because as the blades close,they can produce objectionable whistling due to accelerated air thatmoves through small spaces between the edges. Also, register dampers andregister louvers tend to create rattling noises. Therefore, a needexists for a damper that can easily access existing or new ductwork andmay be adjustable.

Further limitations and disadvantages of conventional, traditional, andproposed approaches will become apparent to one of skill in the art,through comparison of such systems and methods with embodiments of thepresent invention as set forth in the remainder of the presentapplication with reference to the drawings.

SUMMARY OF THE INVENTION

An embodiment of the present invention comprises a boot loadable airdamper device for controlling the flow of air through ductwork. Thedamper device is able to be folded and slipped through a register bootto control airflow. The damper device includes an actuator having aretractable member. The damper device further includes a pivotingmember, wherein the pivoting member is operatively connected to theretractable member of the actuator. The damper device also includes atleast one support base supporting the actuator and the pivoting memberwith respect to each other. The damper device further includes afoldable damper blade attached to the pivoting member, and at least onetensioned hinge member operatively connected to the foldable damperblade. The actuator may be a pneumatic (air pressure) actuator or anelectro-mechanical actuator, in accordance with certain embodiments ofthe present invention. The electro-mechanical actuator may include aportable power supply, for example. The pivoting member may include atleast two pins, for example, nylon pins. The foldable damper blade mayinclude three portions including, for example, a first portion, a middleportion, and a second portion. The foldable damper blade may include asealing member made of, for example, a flexible material. The tensionedhinge member may include a spring. In accordance with an embodiment ofthe present invention, the damper device may further include a foldablesheet member, wherein the foldable sheet member is attached to thesupport base. The foldable sheet member may be magnetic, for example.The damper device may also include a stop member for stopping anunfolding of the foldable damper blade.

Another embodiment of the present invention comprises a method ofinserting a boot loadable air damper device into a ductwork. The methodincludes providing the damper device having an actuator having aretractable member, a pivoting member, wherein the pivoting member isoperatively connected to the retractable member of the actuator, atleast one support base supporting the actuator and the pivoting memberwith respect to each other, and a foldably tensioned damper bladeattached to the pivoting member. The method further includes folding thefoldably tensioned damper blade of the damper device, and inserting thedamper device through a register boot of the ductwork. The method alsoincludes releasing the foldably tensioned damper blade of the damperdevice. The method may further include securing the damper device withinthe ductwork. The method may also include folding a foldable sheetmember of the damper device before inserting the damper device through aregister boot of the ductwork, wherein the foldable sheet member isattached to the support base. The method may further include securingthe damper device within the ductwork using the foldable sheet member.The method may also include operatively connecting an air hose to theactuator before inserting the damper device through the register boot ofthe ductwork. The method may instead include operatively connecting anexternal power source to the actuator before inserting the damper devicethrough the register boot of the ductwork.

A further embodiment of the present invention comprises a register bootloadable air damper device for controlling the flow of air throughductwork. The damper device includes a foldable damper blade and a meansfor pivotally actuating the foldable damper blade. The damper devicefurther includes means for folding and unfolding the damper blade. Themeans for pivotally actuating may be pneumatic or electro-mechanical,for example. An electro-mechanical means for pivotally actuating mayinclude a portable power supply (e.g. a battery). The foldable damperblade may include three portions including, for example, a firstportion, a middle portion, and a second portion. The foldable damperblade may include a sealing member that is made of, for example, aflexible material. In accordance with an embodiment of the presentinvention, the means for folding and unfolding the damper blade includesat least one tensioned hinge member. The tensioned hinge member mayinclude a spring, for example. The damper device may further include afoldable means for securing the damper device to an interior of theductwork. The foldable means for securing the damper device may bemagnetic, in accordance with an embodiment of the present invention. Thedamper device may also include means for stopping an unfolding of thefoldable damper blade. The damper device may further include means forsupporting the foldable damper blade and the means for pivotallyactuating with respect to each other.

These and other features of the claimed invention, as well as details ofillustrated embodiments thereof, will be more fully understood from thefollowing description and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a perspective view of an embodiment of an air damperdevice of the present invention with the damper blade unfolded and in aclosed position;

FIG. 2 illustrates a perspective view of the damper device of FIG. 1with the damper blade unfolded and in an open position;

FIG. 3 illustrates a perspective view of the damper device of FIG. 1with the damper blade partially folded;

FIG. 4 illustrates a perspective view of the damper device of FIG. 1with the damper blade completely folded;

FIG. 5 illustrates a top perspective view of the damper device of FIG. 4with the damper blade completely folded;

FIG. 6 illustrates a rear perspective view of the damper device of FIG.1 with the damper blade completely folded;

FIG. 7 illustrates a side perspective view of the damper device of FIG.1 with the damper blade completely folded;

FIG. 8 illustrates a side, cross-sectional view of the damper device ofFIG. 1 with the damper blade completely folded;

FIG. 9 illustrates the folded damper device of FIGS. 4-8 being insertedthrough a register boot and into a ductwork, in accordance with anembodiment of the present invention; and

FIG. 10 illustrates the inserted damper of FIG. 9 installed and unfoldedwithin a ductwork.

DETAILED DESCRIPTION

FIG. 1 illustrates a perspective view of an embodiment of an air damperdevice 10 of the present invention with the damper blade unfolded and ina closed position. In accordance with an embodiment of the presentinvention, the damper device 10 is intended to be installed through aregister boot of a ductwork (see FIG. 9) and is further intended tooperatively interface to an electronic controller via an air pumpdevice. The damper device 10 includes an actuator 100 having aretractable member 110, and a pivoting member 120 operatively connectedto the retractable member 110 of the actuator 100. The damper device 10also includes a support base 130 supporting the actuator 100 and thepivoting member 120 with respect to one another. The damper device 10further includes a foldable damper blade 160 attached to the pivotingmember 120, and a tensioned hinge member 170 operatively connected tothe foldable damper blade 160. The foldable damper blade 160 is intendedto be folded by a user's hand, by squeezing and keeping the blade 160 ina folded position in preparation for installation. When released by theuser, the damper blade 160 unfolds as is described later herein.

The pivoting member 120 may be constructed of a plastic or metallicmaterial that may be strong enough to withstand pressures or externalforces that may be exerted on the damper device 10. Moreover, thepivoting member 120 may include pivoting pins 190 that allow thepivoting member 120 to be connected to the retractable member 110 andthe support base 130. FIG. 1 illustrates two pivoting pins 190, however,one pivoting pin or more than two pivoting pins may be envisioned andconstructed in a manner that facilitates the pivoting action of thepivoting member 120. The pivoting pins 190 may provide a smooth“self-lubricating” hinge that limits the amount of foreign materialbuild-up. An example of such a pivoting pin may be a nylon pivoting pin,however, other materials may also be used such as plastics, metals,polymers, or any other material that may be used to create a pivotingpin that may be known to one of ordinary skill in the art.

With continued reference to FIG. 1, the support base 130 supports theactuator 100 and the pivoting member 120 with respect to one another.The support base 130 may be constructed from a single, monolithic unit,or the support base 130 may be constructed of multiple members that mayadd additional stability, flexibility, and/or positioning. The supportbase 130 may be made of a rigid material such as hard plastics, metals,or polymers. The damper device 10 may further include a foldable sheetmember 140 that may be attached to the support base 130, for example.The foldable sheet member 140 may be attached to the support base 130 bystaples, screws, nails, fasteners, wire, or any other method ofattachment known to one of ordinary skill in the art. The foldable sheetmember 140 may be foldable to allow easier access into particularlynarrow ductwork. The foldable sheet member 140 may also fasten thedamper device 10 to the ductwork. For example, the foldable sheet member140 may be made of a rubber-type substance that may have high frictionalproperties. The high frictional properties will grip the walls of theductwork, and in turn, “fasten” the damper device 10 to the walls of theductwork. The foldable sheet member 140 may also be made of a magneticmaterial that may allow the damper device 10 to “fasten” onto the wallsof the ductwork. The foldable sheet member 140 may also be made ofmaterials known to one of ordinary skill in the art that allows thefoldable sheet member 140 to secure itself onto the ductwork.

With reference to FIGS. 1 and 2, wherein FIG. 2 illustrates aperspective view of the damper device of FIG. 1 with the damper bladeunfolded and in an open position, the foldable damper blade 160 may bein the shape of a circle or an ellipse, as shown in FIG. 1. However, thefoldable damper blade 160 may also be a square, a rectangle, or anoblong shape that fits a ductwork passage and obstructs or reduces theflow of air through the ductwork. The foldable damper blade 160 may alsobe constructed from a single, monolithic unit or from multiple pieces.In an embodiment of the present invention, the foldable damper blade 160may be made from a single, monolithic unit, then the foldable damperblade 160 may have lines, perforations, slits, path, or any othersection that allows the foldable damper blade 160 to bend, so that thefoldable damper blade 160 may fold. In another embodiment of the presentinvention, the foldable damper blade 160 may be made from multiplemembers, wherein the multiple members are attached to one another toform the foldable damper blade 160, as shown in FIG. 2. The foldabledamper blade 160 may be made of a hard material such as a hard plastic,metal, polymer, or any other hard material known to one of ordinaryskill in the art.

Additionally, the foldable damper blade 160 may further include asealing member 150 (e.g., a gasket), which may be a flexible material,such as rubber, that encompasses the periphery of the foldable damperblade 160. The sealing member 150 may be in the same shape as thefoldable damper blade 160, but may be larger than the foldable damperblade 160, as shown in FIG. 2. This allows the sealing member 150 tocome into contact with the walls of the ductwork before the foldabledamper blade 160 comes into contact. The foldable damper blade 160 maybe a hard material and may cause a “rattling” noise if it were to comeinto contact with the ductwork since moving air causes vibrations. Thesealing member 150 may be a flexible material that may not rattleagainst the ductwork and that may conform to the ductwork in order toform a more “air tight” seal. Moreover, the foldable damper blade 160may be attached to the sealing member 150 by tape, glue, rivets, screws,nails, staples, or any other method of attachment known to one ofordinary skill in the art. This embodiment of the present invention mayallow the foldable damper blade 160 to be placed upon and attached tothe sealing member 150, which may also allow a multiple piece, foldabledamper blade to retain a desired shape and retain foldable capabilities.

With continued reference to FIG. 1, only one hinged tension member isshown and the tensioned hinge member 170 is shown on the side of thefoldable damper blade 160 facing the actuator 100. However, variousembodiments of the present invention may include more than one hingedtension members where the tensioned hinge member 170 is on the side ofthe foldable damper blade 160, facing away from the actuator 100. Anexample of an embodiment of the present invention may include two hingedtension members on either or both sides of the foldable damper blade160. Larger, heavier foldable damper blades 160 may require larger ormore tensioned hinge members 170 to efficiently “fold” and “unfold” thefoldable damper blade 160. As the foldable damper blade 160 is folded orretracted, as shown in FIG. 4, the tension force created by thetensioned hinge member 170 increases, thereby creating a potential ofstored energy. This potential of stored energy may be stored in a springor any other component that may store energy known to one of ordinaryskill in the art. When the foldable damper blade 160 is released, thetensioned hinge member 170 forces the foldable damper blade 160 toreturn to an “unfolded state,” as shown in FIG. 1, for example.

With continued reference to FIG. 2, the damper device 10 may furtherinclude a stop member 200 that may be attached to the foldable damperblade 160 by a fastener such as a rivet, nail, staple, glue, tape,screw, or any other fastener known to one of ordinary skill in the art.The stop member 200 may be made of a rigid material such as a hardplastic, metal, polymer, or combination thereof. The rigid material ofthe stop member 200 may be strong enough to withstand the force createdby the tensioned hinge member 170 so that the stop member 200 does notbend or change its shape. The stop member 200 restricts the motion or towhat extent the foldable damper blade 160 may “unfold.” As the tensionedhinge member 170 exerts a force on the foldable damper blade 160, thestop member 200 exerts an opposing force that restricts how far thefoldable damper blade 160 may extend. Once the foldable damper blade 160has extended to its maximum “unfolded” position, the foldable damperblade 160 may be in a position to restrict air flow in the duct work.Moreover, FIG. 2 shows the stop member 200 as being rectangular inshape, however, the shape of the stop member 200 may also be a circle,square, irregular shape, or any other shape known to one of ordinaryskill in the art that may restrict the foldable damper blade's 160movement.

With reference to FIGS. 3-7, FIG. 3 illustrates a perspective view ofthe damper device 10 of FIG. 1 with the damper blade 160 partiallyfolded. FIG. 4 illustrates a perspective view of the damper device 10 ofFIG. 1 with the damper blade 160 completely folded. FIG. 5 illustrates atop perspective view of the damper device 10 of FIG. 4 with the damperblade 160 completely folded. FIG. 6 illustrates a rear perspective viewof the damper device 10 of FIG. 1 with the damper blade 160 completelyfolded. FIG. 7 illustrates a side perspective view of the damper device10 of FIG. 1 with the damper blade 160 completely folded.

FIG. 8 illustrates a side, cross-sectional view of the damper device 10of FIG. 1 with the damper blade 160 completely folded. The actuator 100also includes an internal actuator member 210 attached to one end of theretractable member 110. As the internal actuator member 210 moves fromone end of the actuator 100 to the other end, the internal actuatormember 210, in turn, moves the retractable member 110 from a firstposition to a second position. This motion gives the retractable member110 its ability to retract and to move back and forth. The actuator 100may further include an adaptor 180 that may facilitate the actuator's100 ability to actuate the internal actuator member 210. For example, inan embodiment of the present invention, the actuator 100 may be an airpressurized actuator, wherein the adapter 180 facilitates the passage ofair into the actuator 100 in order to become pressurized. The supply ofair may come from an air pump or air supply, not shown in the figures,which is controlled by an electronic controller, for example. In anotherembodiment of the present invention, the actuator 100 may be driven byelectro/mechanical methods, such as a motor, wherein the adapter 180 mayaccept electrical lines to power the actuator 100 from, for example, anelectronic controller. Additionally, in the embodiment where theactuator 100 is an electro/mechanical actuator, its power source mayalso include a battery or an external power supply. The actuator 100 mayalso be constructed from a material that is strong enough to withstandconstant change in pressure or friction caused by internal parts. Someexamples of such materials may include hard plastics, metals, polymers,and any other material known to one of ordinary skill in the art.

With continued reference to FIGS. 4-6, a user may “fold” the foldabledamper blade 160 and the foldable sheet member 140 to compact the damperdevice 10. Once the user has “compacted” the damper device 10 byfolding, the user may then attach an air supply or electronic controllerto the damper device 10 and insert the damper device 10 into a ductworkthrough, for example, a register boot of the ductwork. FIG. 9illustrates the folded damper device 10 of FIGS. 4-8 being insertedthrough a register boot 910 and into a ductwork 920, in accordance withan embodiment of the present invention. Once the damper device 10 ispositioned to its proper position within the ductwork, the user may then“release” the damper device 10, thereby “unfolding” the foldable sheetmember 140 and the foldable damper blade 160. The foldable sheet member140 may then grip, fasten, or attach itself to the wall or walls of theductwork 920, thereby securing the damper device 10 to the ductwork 920as shown in FIG. 10. FIGS. 1 and 3 clearly show the sheet member 140 ina curved or semi-circular configuration as if conforming to the interiorwalls of a circular ductwork. In an embodiment of the present inventionwhere a foldable sheet member is not present, the support base 130 maygrip, fasten, or attach itself to the wall or walls of the ductwork,thereby securing the damper device 10 to the ductwork. Releasing the“folded” damper blade 160 causes the tensioned hinge member 170 todeploy or unfold the damper blade 160 into an “unfolded” position, asshown in FIGS. 1, 2, and 10.

Once the damper device 10 is positioned in the ductwork and the foldabledamper blade 160 “unfolded,” the user may then position the foldabledamper blade 160 by utilizing the actuator 100. In an embodiment of thepresent invention wherein the actuator 100 is driven by air pressure,the user may attach an air supply hose to the adapter 180 beforeinserting the damper device 10 into the ductwork, in order to inject airinto the actuator 100 from an air pump. Depending on the amount and/orduration of air added into the actuator 100, the foldable damper blade's160 position, with respect to the actuator 100, may change between afirst position that may allow the most amount of air flow through theductwork, as shown in FIG. 2, and a second position that may allow theleast amount of air flow through the ductwork, as shown in FIG. 1. Asair is injected into (or sucked out of) the actuator 100, the internalactuator member 210 begins to move the retractable member 110, therebypivoting the pivoting member 120 and adjusting the foldable damper blade160.

In another embodiment of the present invention wherein the actuator 100is powered by electricity, the user may “plug” the actuator 100 into apower source such as a battery, an electronic controller providingpower, or any other power source known to one of ordinary skill in theart capable of providing the appropriate electrical power. Depending onthe utilization of a power supplied actuator that may retract and extendthe retractable member 110, the foldable damper blade's 160 position,with respect to the actuator 100, may change between a first positionthat may allow the most amount of air flow through the ductwork, asshown in FIG. 2, and a second position that may allow the least amountof air flow through the ductwork, as shown in FIG. 1. As the actuator100 sets into motion the internal actuator member 210, the internalactuator member 210 begins to move the retractable member 110, therebypivoting the pivoting member 120 and adjusting the foldable damper blade160 within the ductwork.

In summary, a foldably tensioned boot loadable air damper device forcontrolling the flow of air through ductwork, and a method of installingsame are disclosed. The damper device includes an actuator having aretractable member and a pivoting member, wherein the pivoting member isoperatively connected to the retractable member of the actuator. Thedamper device also includes at least one support base supporting theactuator and the pivoting member with respect to each other, a foldabledamper blade attached to the pivoting member, and at least one tensionedhinge member operatively connected to the foldable damper blade forunfolding the damper blade. The damper device may be loaded through aregister boot and into a ductwork when folded.

While the claimed subject matter of the present application has beendescribed with reference to certain embodiments, it will be understoodby those skilled in the art that various changes may be made andequivalents may be substituted without departing from the scope of theclaimed subject matter. In addition, many modifications may be made toadapt a particular situation or material to the teachings of the claimedsubject matter without departing from its scope. Therefore, it isintended that the claimed subject matter not be limited to theparticular embodiment disclosed, but that the claimed subject matterwill include all embodiments falling within the scope of the appendedclaims.

What is claimed is:
 1. A boot loadable air damper device for controllingthe flow of air through ductwork, the damper device comprising: anactuator having a retractable member; a pivoting member, wherein saidpivoting member is operatively connected to said retractable member ofsaid actuator; at least one support base supporting said actuator andsaid pivoting member with respect to each other; a foldable damper bladeattached to said pivoting member; and at least one tensioned hingemember operatively connected to said foldable damper blade.
 2. The bootloadable air damper device as defined in claim 1, wherein said actuatoris an air pressure actuator.
 3. The boot loadable air damper device asdefined in claim 1, wherein said actuator is an electro-mechanicalactuator.
 4. The method of claim 3, wherein said electro-mechanicalactuator further comprises a portable power supply.
 5. The boot loadableair damper device as defined in claim 1, wherein said pivoting memberfurther comprises at least two pins.
 6. The boot loadable air damperdevice as defined in claim 5, wherein said at least two pins are nylonpins.
 7. The boot loadable air damper device as defined in claim 1,wherein said foldable damper blade comprises at least three portions. 8.The boot loadable air damper device as defined in claim 7, wherein saidat least three portions is a first portion, a middle portion, and asecond portion.
 9. The boot loadable air damper device as defined inclaim 1, wherein said foldable damper blade further comprises a sealingmember.
 10. The boot loadable air damper device as defined in claim 9,wherein said sealing member is made of a flexible material.
 11. The bootloadable air damper device as defined in claim 1, wherein said at leastone tensioned hinge member includes a spring.
 12. The boot loadable airdamper device as defined in claim 1, wherein said damper device furthercomprises a foldable sheet member, wherein said foldable sheet member isattached to said at least one support base.
 13. The boot loadable airdamper device as defined in claim 12, wherein said foldable sheet memberis a magnetic foldable sheet member.
 14. The boot loadable air damperdevice as defined in claim 1, wherein said damper device furthercomprises a stop member.
 15. A method of inserting a boot loadable airdamper device into a ductwork, the steps comprising: providing saiddamper device having an actuator having a retractable member, a pivotingmember, wherein said pivoting member is operatively connected to saidretractable member of said actuator, at least one support basesupporting said actuator and said pivoting member with respect to eachother, and a foldably tensioned damper blade attached to said pivotingmember; folding said foldably tensioned damper blade of said damperdevice; inserting said damper device through a register boot into saidductwork; and releasing said foldably tensioned damper blade of saiddamper device.
 16. The method of claim 15 further comprising securingsaid damper device beyond said register boot within said ductwork. 17.The method of claim 15 further comprising folding a foldable sheetmember of said damper device before inserting said damper device througha register boot of said ductwork, wherein said foldable sheet member isattached to said at least one support base.
 18. The method of claim 17further comprising securing said damper device within said ductworkusing said foldable sheet member.
 19. The method of claim 15 furthercomprising operatively connecting an air hose to said actuator beforeinserting said damper device into through a register boot of saidductwork.
 20. The method of claim 15 further comprising operativelyconnecting an external power source to said actuator before insertingsaid damper device through said register boot of said ductwork.
 21. Aboot loadable air damper device for controlling the flow of air throughductwork, the damper device comprising: a foldable damper blade; meansfor pivotally actuating said foldable damper blade; and means forfolding and unfolding said damper blade.
 22. The boot loadable airdamper device as defined in claim 21, wherein said means for pivotallyactuating is pneumatic.
 23. The boot loadable air damper device asdefined in claim 21, wherein said means for pivotally actuating iselectro-mechanical.
 24. The boot loadable air damper device as definedin claim 23, wherein said electro-mechanical means for pivotallyactuating includes a portable power supply.
 25. The boot loadable airdamper device as defined in claim 21, wherein said foldable damper bladecomprises at least three portions.
 26. The boot loadable air damperdevice as defined in claim 25, wherein said at least three portionsincludes a first portion, a middle portion, and a second portion. 27.The boot loadable air damper device as defined in claim 21, wherein saidfoldable damper blade further comprises a sealing member.
 28. The bootloadable air damper device as defined in claim 27, wherein said sealingmember is made of a flexible material.
 29. The boot loadable air damperdevice as defined in claim 21, wherein said means for folding andunfolding said damper blade includes at least one tensioned hingemember.
 30. The boot loadable air damper device as defined in claim 29,wherein said at least one tensioned hinge member further comprises aspring.
 31. The boot loadable air damper device as defined in claim 21,wherein said damper device further comprises a foldable means forsecuring said damper device to an interior of said ductwork.
 32. Theboot loadable air damper device as defined in claim 31, wherein saidfoldable means for securing is magnetic.
 33. The boot loadable airdamper device as defined in claim 21, wherein said damper device furthercomprises a means for stopping an unfolding of said foldable damperblade.
 34. The boot loadable air damper device as defined in claim 21further comprising means for supporting said foldable damper blade andsaid means for pivotally actuating with respect to each other.